Indirect-heat thermal processors such as heaters or dryers may utilize hot gases for heating or drying bulk solids as the bulk solids flow through the heater or dyer. The use of hot air is inefficient as large volumes of hot air are utilized and waste heat in the exhaust air is difficult to recover.
Heat transfer plates or tubes provide improved efficiency in heat exchangers by indirectly heating bulk solids that flow, under the force of gravity, through a heat exchanger. The heat transfer plates or tubes include a heating fluid flowing through the plates or tubes and the bulk solids are heated as they flow through spaces between adjacent heat transfer plates. Such heat transfer plates and systems for heat transfer plates and tubes require a complex construction and control to maintain the temperature of the heating fluid at a desirable temperature for treatment of the bulk solids flowing between the heat transfer plates.
Improvements in indirect-heat thermal processors are desirable.